The ground water is high, so rainwater has difficulty seeping into the ground.
If November and December become normal in terms of precipitation, 2023 will be the wettest year in Danish weather history .
Up to and including October 2023, we have received 776.6 millimeters of rainfall nationally, and November and December give a combined 141.2 millimeters of rainfall according to the climate normal for the 30-year period from 1991 to 2020.
If you add the numbers together, we end up with over 905 millimetres, which is the largest rainfall total for a calendar year so far. That amount was measured in both 1999 and 2019.
With a normal amount of rainfall, we can therefore break the previous annual record for wet weather.
If you subsequently look at the long-term forecasts, there is, however, a clear signal that November offers a rainfall amount around or above normal.
And although reliability is low when we look even further into the future, there are also trends for precipitation amounts around or above normal in December.
Overall, one must therefore conclude that the forecasts indicate that the normal amount of precipitation or more may fall in the last two months of the year, and thus both statistics and weather models suggest that 2023 will be record wet.
Increases the risk of flooding
It is bad news in terms of flooding in the coming months, because the groundwater is high after the recent heavy rain. In the past four months, we have received an average of more than 100 millimeters of rain per month.
When the ground water due to large amounts of rain rises all the way to the surface, typical climate solutions that direct surface water into the ground no longer work, and then it does not take much rain to cause local floods.
However, the record is not yet a given, because the forecasts can change quickly when we enter December. Here, the weather begins to be affected by what happens up in the stratosphere, which is the layer above the troposphere, where we are.
If we get a sudden warming up there at an altitude of 15 to 30 kilometers, something that forecast models notoriously struggle to predict well in advance, it could lead to cold and dry weather conditions down at the ground level here, and then the month could end with less precipitation than normal .
All other things being equal, however, 2023 is on track to be one of the wettest years in weather history, which began in 1874 for Denmark, and we have to get used to the fact that it will increasingly become the norm. According to the scenarios for the future climate in Denmark, we should expect more precipitation in the winter.